Covering device that can be unscrewed

摘要

The cap has an oblique relief component (4) on its inner surface which cuts a spiral groove in the plastic component when it is fitted in place, forming a threaded surface which allows the cap to be removed for recycling purposes. The relief component can be made, for example, in the shape of at least one rib, and the inner surface of the cap and outer surface of the plastic component are of more or less than same diameter.